


Forever By Your Side

by MoonytheMarauder1



Category: Harry Potter - J. K. Rowling
Genre: Alternate Universe - Assassins & Hitmen, Angst and Hurt/Comfort, Assassins & Hitmen, Attempted Murder, Bisexual Remus Lupin, F/M, Flashbacks, Gay Sirius Black, Immortality, Implied/Referenced Character Death, M/M, Tea, Violence
Language: English
Status: Completed
Published: 2020-06-07
Updated: 2020-06-07
Packaged: 2021-03-04 07:09:27
Rating: Teen And Up Audiences
Warnings: Graphic Depictions Of Violence
Chapters: 1
Words: 4,078
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/24589612
Author URL: https://archiveofourown.org/users/MoonytheMarauder1/pseuds/MoonytheMarauder1
Summary: When Sirius is told to take care of a mark, he doesn't hesitate. But there's more to Remus Lupin than meets the eye—so much more.
Relationships: Sirius Black/Remus Lupin, past Remus Lupin/Nymphadora Tonks - Relationship
Comments: 4
Kudos: 43





	Forever By Your Side

**Author's Note:**

> Hey, y'all! Technically, I should've published this days ago, but we're going to pretend that I have my life together and cross-posted it from ffn to here at the right time. :P
> 
> Anyway. Inspired by Tuck Everlasting, enough that it's probably best to consider it an AU. 
> 
> Enjoy!

_Sirius readied the knife in his hand, his breathing deep and slow. Peering through the bushes, he watched his target. The man in question was kneeling in the soft dirt, gardening a little plot of land. His movements were calm and assured; he didn't suspect a thing._

_Grey eyes narrowed as Sirius prepared to strike. He wasn't sure why he'd been assigned to this mark—the man seemed completely harmless—but Sirius knew better than to question orders. Still, regret twisted inside of him, burning hot and uncomfortable._

_But he had a job to do, and it was time to do it._

_Using the speed and agility he was known for in his field, Sirius leapt from the bushes and grabbed the man from behind. Then, without any further hesitation, he plunged the knife deep into the man's gut and twisted the blade. There was a sharp intake of breath, and Sirius waited for the man to collapse against him… but he never did._

_In fact, Sirius might as well have been hugging the man for all the reaction he'd received._

" _That's not going to work." The man's voice was quiet and full of—regret?_

_Sirius let go of the knife handle. This wasn't right. His blade was inside of this man; he should have fallen to the ground, or at the very least stumbled. But there had been nothing except that gasp of surprise._

_The man didn't turn around as Sirius backed away. Something else was off, something else wasn't as it should be—and then he realized: there was no blood._

" _What the_ hell _," he spat out, eyes wide. Forget his mission, forget his superiors—this man was an entirely new kind of dangerous._

_Panic overtook him, and the only thing Sirius could think to do was run. Unfortunately, he was startled off of his game. He took one wrong step and went sprawling, then hit his head painfully against the side of the cabin._

_The last thing Sirius saw before everything went black was a pair of beautiful amber eyes._

* * *

"You swore to me this would never happen."

Sirius turned around guiltily. Remus' voice was filled with anger, and his posture was stiff with rage. Sirius didn't move, though; he had to do this. He'd made up his mind. So he lifted his chin and stared Remus down.

"I know what I'm doing. You can't stop me."

"Sirius." Remus crossed the room and reached for the cup in Sirius' hands; he kept it out of the scarred man's grasp. "I told you, it's a terrible curse! It isn't worth it."

"It doesn't have to be like that," Sirius protested. "The difference, Remus, is that we'll be together this time. It'll be you and me—"

"I can't let you do this." Remus tugged anxiously at his tawny curls, distress crossing his features. "I can't let you make the same mistake I did. I can't watch you be miserable for eternity!"

"But I can't leave you knowing that you're stuck here!" Sirius set down the tea and hurried over to Remus, taking the short man's face in his hands. "You're searching for a solution. Let me help you do that. However long it takes, Remus, I'm willing to stand by your side."

Remus' amber eyes sparkled with unshed tears. "You'll hate me," he whispered. "Maybe next year, maybe in fifty years, but you'll hate that you fell in love with me enough to do this."

Slowly, Sirius shook his head. There was so much he didn't know about life, but he was certain about one thing. "I could never regret loving you."

* * *

_When Sirius opened his eyes again, it took him several seconds to realize that he was indoors. And in a bed. And alive._

_Gingerly, Sirius lifted a hand to the wound on his head. It had been bandaged with care, his long, black hair carefully combed back. It still hurt like hell, but Sirius knew from experience that things could have been much worse._

_He winced as he recalled his fall. That hadn't been his finest moment._

_He looked around. He was lying on a small bed with simple white sheets. The cottage was modest, decorated only with the bare essentials—or so he thought, until he realized that bookshelves lined every wall. It was enough to distract him from the problem at hand; he'd never seen so many books in one place._

_Sirius was so busy gaping at the sight, in fact, that he didn't notice the man come in through the door._

" _I know what you're doing."_

_Startled, Sirius reached for one of the knives that was hidden in his coat, only to discover that he'd been disarmed._

_The man noticed his action. "Sorry," he said, sounding apologetic, "but I really didn't fancy being stabbed again. You've no idea how uncomfortable it is."_

" _Uncomfortable," Sirius repeated dumbly. He wondered if he'd hit his head harder than he'd thought. "You—you should be dead." His breathing became more rapid as he recalled plunging his knife into this man's belly; he wasn't showing any signs of the injury. "What the_ hell _are you?"_

_A flicker of pain crossed the man's scarred face. He looked away for a moment, then picked up a nearby kettle that Sirius didn't realize had been boiling. As he poured the tea, the man spoke. "My name is Remus," he murmured. "But I can assure you that I'm completely human."_

" _Right." Sirius couldn't keep the scorn from his voice, but there was something about Remus' movements that put him a little more at ease. He'd had every opportunity to kill Sirius while he slept, but hadn't. And as he made the tea, there was a tiredness about his stance that made Sirius pity him: this wasn't a man who was seeking revenge. This was a man crippled by exhaustion._

_Remus' amber eyes—such an unusual color—flitted over to meet Sirius'. "I am," he insisted. He walked over and held out a cup to Sirius. "Drink. You'll feel better."_

_Sirius eyed it distrustfully. "I tried to kill you," he said slowly._

_Remus tilted his head to the side. "Yes?"_

_Sirius sucked in a breath, his eyes darting about. "So I highly doubt you want to help me heal," he ground out. His mind was racing as he tried to figure out Remus' angle. "Tell me what it is you want."_

_Remus pointedly took a sip from the cup he'd offered Sirius, a single brow raised. "I don't want anything from you. If anything, I'd like to apologize; it seems you weren't well-briefed before they sent you here."_

_That gave Sirius pause. "You… know about that?"_

_Remus shrugged. "You're not the first they've sent to kill me. But, as you've undoubtedly noticed…" Remus gestured at himself. "It's a little harder than they make it out to be."_

_Sirius' head was spinning. As much as he'd love the tea—it smelled delicious, and he could use the warm beverage to settle his nerves—if a knife wound couldn't harm Remus, he doubted poison could. But he was trying to piece all of this together._

_Remus couldn't be hurt. He said there had been people sent to kill him before, but they'd evidently failed. Sirius knew the sort of people the organization hired to take care of targets—they never missed a mark._

_But what could Remus possibly have done at such a young age to warrant such attention? He didn't appear to be much younger than Sirius; he looked twenty at the most._

" _The other people the organization sent…" Sirius asked slowly. "Did they ever come back?"_

_Remus looked surprised. "Of course they did. Or at least, they left this place. I don't really know what became of them, but I've never held anyone here against their will."_

_He moved to the side to prove his point, clearing the path to the door. And Sirius knew that he should take the opportunity to leave—that he should run out of here because whatever Remus was, it wasn't natural._

_But damn his curiosity, because if there was one thing Sirius couldn't stand, it was an unsolved puzzle, and Remus was quite the enigma. And there was this air about Remus that promised so much. Maybe… maybe it was his kindness._

_No one had treated Sirius with such kindness in… he couldn't remember._

" _I'm Sirius," he confessed._

_After giving a brief nod of acknowledgement, Remus offered him the tea again. Sirius didn't drink it, but he did take the cup; his heart warmed when hope blossomed in Remus' eyes._

* * *

_Time quickly lost meaning. The door was always unlocked, Remus never tried to convince him to stay longer, but Sirius still couldn't bring himself to leave. Every night that he said he'd rest his head another day, Remus looked relieved._

_It took Sirius a bit of time to figure out, but he realized that Remus was miserably lonely._

_So he stayed. But really, Sirius wouldn't miss the chance to watch Remus. He was gentle, kind, and so, so beautiful. He began wondering if Remus was some sort of angel who couldn't be harmed, living on earth for some reason—surely, someone as pure as he couldn't be mortal?_

_Remus laughed when Sirius shared his theory. "That's not it," he'd said. "I told you, I'm completely human, just… stuck."_

_He hadn't elaborated, and Sirius hadn't pushed him. Remus had continued to dress his injury, and the conversation fizzled out._

_But Sirius picked it up again the next day._

" _Are you cursed or something? Undead? A strangely tangible ghost?"_

_Remus paused his gardening. The sunlight made his tawny curls glow, and there was something so attractive about the way Remus peered up at Sirius through his fringe. "Not undead," he murmured. "Not a ghost. Cursed… yes. Some would argue, but I am most definitely cursed."_

_Sirius crouched down, careful not to squash any of the plants Remus was attending. "If you tell me your secret," he whispered, "I'll tell you mine."_

_Remus hesitated. Doubt was written across his features, and Sirius wanted nothing more than to banish his fears. More than anything else in the world, he wanted Remus to trust him._

_He was falling fast and hard, but who could blame him? He was certain that there was no one like Remus on the planet._

" _You wouldn't believe me," Remus said at last, his voice shaking. "And I don't want them coming for you—and they would, if they knew the truth."_

" _I've seen you get stabbed with a knife and not so much as bleed," Sirius pointed out. "I'd believe anything."_

_Remus let out a frustrated huff. "It's not the curse you wouldn't understand," he explained. "It's why I shouldn't share it with you."_

_Confused, Sirius laughed uncertainly. "Why would I want a curse?"_

_A great sadness clouded Remus' eyes. He looked so lost, so pained—Sirius hated to see the expression on his face. "Just trust me, Sirius. It's better, sometimes, to be ignorant."_

_If Remus wanted to dance around the issue, Sirius couldn't do anything about it. But his heart still thundered in his chest when he looked at Remus; he still worried for this man._

" _Maybe," he said softly, getting to his feet, "you should try and trust me."_

* * *

"I…" Remus swallowed. "I could never regret loving you, either, Sirius… but this isn't the way."

"We'll find a cure together," Sirius swore. "I promised that I would stay by you forever, Remus."

A horrible silence stretched between them. Finally, in a tortured whisper, Remus pulled away and said, "You don't have any concept of forever." He wrapped his arms around himself, refusing to look at Sirius. "I don't feel good about this."

Sirius sighed heavily. "When do you feel good about anything? You're determined to punish yourself, Remus, but maybe this is our chance to be happy."

"This won't make you happy," Remus snapped.

"No," Sirius agreed. "But you will."

* * *

" _I've killed people," Sirius said suddenly over dinner one night. He wasn't sure what he was trying to accomplish, exactly, but he was burning to know what ailed Remus. And if sharing his own struggles would open that door… "I'm a hitman, an assassin."_

_He waited for a reaction—horror, maybe, or disgust. But Remus just continued to spoon soup into his mouth. "Yes, I'd gathered as much when you plunged a knife into my stomach."_

_Hiding his disappointment, Sirius dropped his head into his hand. "Why won't you tell me why they want you dead?"_

_Remus' lips thinned. "No one likes people who are different, Sirius."_

" _That's not a good enough reason," Sirius argued. He reached across the table and boldly took Remus' hand in his own; Remus stared at it with wide eyes. "Remus, tell me. Whatever burden you're carrying… share it."_

_Slowly, Remus lifted his eyes to Sirius. "Knowing the answer won't make you any happier," he warned. When Sirius only looked at him expectantly, Remus sighed. Thickly, he answered, "I can't die, Sirius. I've been alive for nearly three hundred years."_

_A silence followed. Sirius felt numb, he felt as though he'd been set on fire—he felt everything and nothing all at once. His first thought was outright denial. How could that be true? It just wasn't possible._

_But he'd already seen the proof. And it would explain Remus' loneliness._

_Once he'd accepted the truth of Remus' words, a million questions flew through his mind. He only voiced one word, though, in a breathy whisper: "How?"_

_Remus stood abruptly. He was breathing shallowly and shaking—he looked angry with himself. "I'll never tell," he said. "I'm sorry, Sirius, I won't. They want me dead because they know I have…_ it _. They just don't understand how invincible it makes me." Remus dragged his hands through his hair, his pupils dilated. "I'm always uprooting my life. I don't age, I can't get hurt—do you know how many times I should have been killed but haven't been? I don't know if I ever will, and that's the most terrifying thought of all."_

_Sirius gaped at him, a cold feeling spreading over his body. "You want to die?"_

_Remus looked at him then, and the raw emotion in his face was overwhelming. Sirius hadn't seen anyone look so haunted, and he'd met many, many troubled people._

_For several horrible minutes, neither man spoke. Remus kept swallowing, as though words he didn't want to speak were crawling up his throat. Sirius didn't know what to think, so he just stared as Remus got himself under control._

" _I had a wife," Remus said at last. "Her name was Nymphadora, but she hated it so much, so I called her Dora. She didn't mind that." Remus' eyes glazed over, and Sirius realized that he was lost in the past. "She was so full of life. I had already been cursed at that point; if I hadn't been, I'd have been eighty when I met her. I didn't think it made sense to fall in love with her, but I couldn't help it. She just… walked into my life and refused to leave._

" _There were all sorts of stories about me, you see. I was young enough then that there were still people in the village that remembered me. I'd tried to stay hidden away once I realized that I wasn't aging, but I couldn't erase myself from the minds of the villagers._

" _Dora loved to investigate rumors. She always wanted to believe that there was magic in this world." Remus' eyes softened as he remembered. "She was a little piece of magic herself, I'm certain. But anyway, she came looking for me, and she found me. I tried so hard to get her to leave, but she was so persistent. She wasn't the kind of person to walk away from what she wanted, and I couldn't help but fall in love with her."_

_Remus wrung his hands together, a small, bittersweet smile on his face. "We married," he said simply. "She aged without me. She had our son, and for a while, the three of us were happy." Then the light in Remus' eyes died. "But they knew I held the secret to eternal life, and we had to run. We were constantly uprooting ourselves, and it… it became too dangerous. I realized that as long as I was with them, they could be used against me."_

_Sirius could imagine it. He pictured Remus staring in horror as some faceless assassin pointed a knife at his son and flinched. "They didn't want to live forever?" he guessed._

_A small shake of the head was his answer. "I begged her not to."_

_Licking his lips, Sirius wondered if he truly wanted to hear the rest of this story. But, like always, his curiosity got the better of him. "Then what happened?"_

_Remus' gaze dropped to the floor, and his entire body stilled. "I said goodbye to them," he murmured. "Dora died a long time ago… so did Teddy. I suppose I may have family around somewhere, but I never looked. I was always… I was always afraid to."_

_For a long time, neither man spoke. There was so much to be said, but at the same time, there was nothing to say. Sirius didn't ask if Teddy had been old enough to remember his father when they said goodbye; he didn't ask if Dora had protested about the separation. The answers to those questions didn't matter._

" _I'm sorry," he said sincerely. "For what it's worth, Remus, I'm sorry."_

 _Remus didn't look up. "It's a_ curse."

_Yes. Yes, Sirius could see that now. "What's the secret, Remus?" he asked quietly. "You're living in the woods like a fugitive… what do they want so badly?"_

_A heavy sigh escaped Remus, all the energy seemingly draining from his shoulders. "I discovered one day, quite on accident, that there is a certain plant that can forever halt the aging process if brewed into tea. Once I connected it back to the plant, I uprooted it. The people who sent you here don't know exactly what they're looking for, just that I hold the key."_

_Sirius blanched. "The plant—the key to eternal life—is here? You've kept it with you all this time?"_

" _I didn't want anyone else to take it by mistake," Remus said, his tone slightly waspish. "And I don't know… I don't know if I'll need it later."_

" _For what?"_

_Remus looked at him strangely. "This plant… it's supposed to have a counterpart. Somewhere on earth, there should be another plant that can undo what's been done."_

" _You're searching for it," Sirius guessed._

" _Yes," Remus admitted. "I don't know if it truly exists, but I have to try."_

_Sirius stared at Remus for a long moment, amazed by the determination in his gaze. He was about to say so to Remus, but the other man spoke before he got the chance._

" _Ah, I seem to recall you promising to tell me your tale if I told you mine."_

_Well, Sirius supposed he did owe the man a story. "It, ah…" He cleared his throat, his mind still reeling from all he'd learned. "It isn't as exciting as yours."_

_Remus sat back down and propped his chin on his fist. "That's what I'm banking on."_

_So Sirius pushed aside all his questions and muddled thoughts about tea that could make one live forever, and he told Remus about being born into a family where nothing less than perfection was accepted. The Blacks, he explained, had been a part of this business for generations, and there really hadn't been any question of whether Sirius would take up the family tradition._

" _They're not a loving bunch, my family," he told Remus dryly. "I'd have done anything to get away from them."_

_Remus frowned sharply at this, but he waved Sirius on._

" _Unfortunately," Sirius continued, "this is the only trade I know, so." He shrugged and looked away, his shame hot and uncomfortable. He'd never grown close enough to anyone to care what they thought of his profession, but Remus… Remus would hardly be impressed._

_Somehow, Remus seemed to read all of this on his face. "You know, Sirius," he said lightly, "I've seen a lot in three hundred years." His amber eyes looked completely sincere. "If there's one thing I've learned, it's that it's never too late to turn your life around."_

_He stood up from the table and left then, but not before he sent a small smile Sirius' way. Sirius watched him go, amazed by this man's capacity for forgiveness—and realized that he was totally and irrevocably in love with him._

_Which led to a terrifying thought: One day, Sirius would die—but Remus would not._

* * *

"You brought light into my life, Remus," Sirius continued. "You made it worth living. You made this world a beautiful place to be."

Remus took a step back and shook his head. When he spoke, bitterness tinged his voice. "No, Sirius. You just had to find your own way. I didn't—"

"But you did," Sirius interrupted. "You're the most incredible man I've ever met, Remus. The most incredible _person_. You're beautiful, inside" —he cupped Remus' face with a hand and ran his thumb over Remus' cheekbone, crossing right over one of the scars on the other man's face— "and out."

Remus' eyes were wide, but he didn't look away from Sirius this time. Sirius knew that Remus had spent too long without company, that he had become accustomed to seeing himself as _other_. But Sirius knew now that no one else in the world was as natural as Remus Lupin.

"You deserve to be loved," Sirius whispered. "Dora knew it. I know it. The difference is, I don't have anyone else to live for. If I leave you now, Remus, my life will be empty. You're the only way I can fill it."

Remus' breathing was labored and there were tears in his eyes, but he leaned into Sirius' touch. "There's no going back, Sirius. A cure might not even exist."

"How could I complain about spending an eternity with you?" Sirius grinned suddenly. "If anything, you'd be the one complaining. I have some terrible habits."

That brought out a weak laugh from Remus, which warmed Sirius' heart.

"I… I suppose I can't stop you," Remus whispered. He looked so afraid—terrified, really—but there was a hope in his eyes that Sirius couldn't ignore. Despite everything, Remus didn't want to watch another love wither away. If Sirius could help it, Remus would never have to witness such a thing ever again.

So he plucked a leaf from the little houseplant on the windowsill. It was so unassuming, one would never suspect that it held such a terrible power. Without hesitation, Sirius dropped it into his tea and let the brew steep. Remus watched him with sad eyes, but he offered no further protest. Sirius tried to comfort him.

"I'm not doing this because I want to live forever," he reminded his partner. "I'm doing this because I'm a selfish man, Remus, and I want you to myself for as long as we both live."

Remus closed his eyes. "I don't want to get you stuck here, Sirius."

"I've never been more sure of anything in my life," Sirius promised, his voice soft. "There's a cure out there, Remus, and we'll find it. It will be our adventure."

Remus' eyes opened again, and he stared at Sirius long and hard. "How do you know?"

"The universe always provides a balance." He said it with the utmost confidence. "If this plant exists, so does its counterpart. But until we find it…" He raised his cup. "I wouldn't mind spending an eternity with you."

He raised the cup to his lips and drank deeply.

* * *

_It took one more week for Sirius to get Remus to kiss him, but it was a kiss worth waiting for._

_Sitting there, his hands on Remus' neck and back and Remus' fisted in his hair, Sirius knew that he'd spend the rest of his life with this man. He'd stay by Remus' side through thick and thin; they'd run from Sirius' family together, and they would search for a cure together._

_All he really had to do now was decide how long he wanted that lifetime to last._

_Deep down, he knew he already had his answer._


End file.
